Double T-shaped steel sheet piling profile

ABSTRACT

The invention relates to a double T-shaped steel piling wall profile ( 1 ), which is produced by hot rolling and which has two flange sections ( 3 ) that are centrally joined via a connecting member ( 8 ). The flange sections have connecting end sections ( 4 ), which are adjoined thereto and which have a club-shaped design.

BACKGROUND OF THE INVENTION

The invention relates to a double T-shaped steel piling wall profile.

Double T-shaped piling wall profiles are known, for example, as Peinersteel piling walls (see, for example, section of the delivery program“Hoesch Stahlspundwände” January 2003 [“Hoesch Steel Piling Walls”]and/or “Peiner Stahlspundwände” March 2002 [“Peiner Steel PilingWalls”], available from HSP Hoesch Spundwand und Profil GmbH, Dortmund,Germany).

These company brochures describe hot-rolled piling wall profiles withtwo flange sections which are connected in the center by a web.Club-shaped connecting end sections adapted to receive interlocks adjointhe flange sections. The flange sections are oriented at least on theoutside essentially horizontally. The inside of the flange can have awedge-shaped taper from the flange center to the flange end, or can,like the outside of the flange, extend essentially horizontally.

The input stock for these piling wall profiles produced by hot rollingis in the form of either slabs, blocks or so-called beam blanks, whereinthe latter are cast with a cross-section that is close to the finaldimensions.

When using a heated slab or a block, the essentially rectangularcross-section is transformed in a shaping mill into a shape that isclose to the final dimensions of the double-T profile, and subsequentlyrolled to the desired final dimension in a finishing mill stage, whichincludes at least a universal mill and an edger. When using the beamblanks, blooming can be limited to a few reduction passes, because thedimensions of the cast cross-section are already close to the finaldimensions.

The finishing mill stage consists of a roller set for machining theoutside and the inside of the rough profile.

The double T-shaped piling walls are used, for example, for supportingsudden height changes in the terrain and for shoring up trenches andport facilities. The piling wall profiles must be able to withstandlarge horizontal forces which cause a corresponding bending load of thepiling walls perpendicular to the piling wall wall. The dimensions aretypically determined by the bending load which the piling wall profilemust be able to absorb from the lateral earth and/or water pressure viathe section modulus.

Depending on the load to be absorbed, the piling wall profiles can beconnected via the interlocks either with one another, thereby producinga closed wall from individual support elements with a high sectionmodulus, or the piling wall profiles can be used as a mixed piling wall,whereby for example U-shaped or Z-shaped fill elements are connected bythe interlock to the double T-shaped profile. In the latter case, onlythe double T-shaped profiles function as support elements, whereas thefill elements essentially only perform a sealing function.

Double T-shaped piling wall profiles are offered essentially indifferent lengths and with flange sections having different wallthicknesses, depending on the required section modulus.

The club-shaped connecting end sections of the flange typically have astandard geometry, so that all standard profiles can be connected witheach other or in combination with other profiles by using a singleinterlock.

The commercially available standard piling wall profiles frequently donot satisfy the section moduli required by a static design. For example,a standard delivery program of a company may not be able to deliver apiling wall profile with a required section modulus, or the requiredsection modulus may fall between two available standard piling wallprofiles.

If the required section modulus falls between two available standardpiling wall profiles, then it makes often no economic sense to selectthe next larger profile which may be significantly more expensive. If astandard delivery program is unable to supply the required sectionmodulus, then a completely new piling wall profile may have to beproduced.

For producing a new piling wall profile by hot rolling, an expensiveroller set must be procured at least for the finishing mill stage, and alarge inventory may be required and expensive rolling tests, until ahigh-quality product is ready for sale.

The present technology offers various possibilities for increasing thesection modulus of a standard profile, without having to either selectan uneconomical profile or to produce an entirely new profile with adifferent geometry (essentially related to the overall height and theflange thickness), which would be a complex and expensive process.

To eliminate these disadvantages, attempts have been made to increasethe section modulus according to the customer requirements whilemaintaining the geometry of the standard profile.

In one embodiment, which has been used and proven effective in practice,steel lamellae have been welded to one or both exterior flange surfacesof the piling wall profile (see excerpts from the delivery program“Peiner Stahlspundwände” March 2002) [“Peiner Steel Piling Walls”].These lamellae are preferably arranged in the region of the highestbending moment.

Welding these lamellae is expensive and adds costs, because the pilingwall profile must be straightened due to the welding stress.

In another approach, the section modulus of a standard profile can beincreased to attain a greater average wall thickness in the flange bymoving the finishing rollers apart during the rolling process (seeexcerpts from the delivery program “Hoesch Stahlspundwände” January 2003or “Peiner Stahlspundwände” March 2002).

The flange thickness of wedge-shaped flange sections is given as anaverage value which corresponds to the cross-sectional area of theflange divided by the overall width of the profile. The average wallthickness of profiles with parallel flanges corresponds to the nominalwall thickness in the flange section.

The size of the opening between the outside rollers of the finishingroller stage which determines the average flange thickness is increasedby a value in the range of millimeters, which increases the overallheight of the profile and hence also the average wall thickness of theflange.

Disadvantageously, the pass of the outer rollers also enlarges theclub-shaped geometry of the connecting end section, in addition toincreasing the average flange thickness.

The tolerances in the connecting region are relatively tight to enablethe club-shaped section to securely engage with the standard interlockto withstand the load on the piling wall. If the average wall thicknessincreases too much, then the dimension of the club-shaped section wouldalso increase to a point where the standard interlock can no longer bepushed over the club-shaped section.

With this approach, new interlocks would have to be produced which canbe quite expensive.

It is therefore an object of the invention to provide a piling wallprofile which can overcome the aforedescribed disadvantages ofconventional profiles.

SUMMARY OF THE INVENTION

According to the teachings of the invention, the object is solved by adouble T-shaped piling wall profile, where the average wall thicknessfor a defined standard profile is increased in the flange sections whilemaintaining a constant dimension of the connecting end section, with theincrease in the average wall thickness being produced by hot rolling thepiling wall profile.

The invention also relates to a double T-shaped piling wall profile madeof steel and produced by hot rolling, with two flange sections connectedin the center by a web, with adjoining club-shaped connecting endsections adapted to receive interlocks, wherein one or both flangesections have a convex bulge between the club-shaped connecting endsections, as viewed in cross-section.

The term “convex-like” is meant to indicate an embodiment where, forexample, the bulge is arcuate, or increases and then decreases again inthe form of an arch and is linear in the intermediate region, orincreases and then decreases again linearly in the intermediate region,while also being linear in the intermediate region.

Increasing the wall thickness only in the flange section has theadvantage that even large increases in the wall thickness can beproduced cost-effectively by hot rolling, without changing thedimensions club-shapes sections. This eliminates the otherwise highcosts associated with welding the lamellae or providing new interlocks.

The wall thickness according to the invention is increased during hotrolling preferably in the finish rolling stage, wherein the finishrollers for machining the outside of at least one outer surface of theflange have a surface contour necessary to produce the increased wallthickness.

According to another advantageous feature of the invention, theincreased wall thickness can be produced on the outside and/or inside onone or both flange sections.

This approach can significantly enhance the flexibility to meet theaesthetical or technical customer requirements.

According to another advantageous embodiment, the increase in the wallthickness can be obtained with commercially available piling wallprofiles having either parallel or non-parallel flanges.

The increase in the wall thickness of only the flange section producedaccording to the invention during hot rolling gradually changes overinto the club-shaped connecting end section via a step-less transition.

This approach advantageously eliminates a transition having relativelysharp edges, which are produced, for example, when welding lamellae onto a rectangular cross-section, which can cause stress- andcorrosion-related problems.

In another advantageous embodiment, the step-less transition includes aconically tapered section and an arcuate section adjoining theconnecting end section.

The surface contour of the increased wall thickness can be adapted toany shape and form required by the customer. Feasible are, for example,an essentially rectangular or concave or convex surface contour.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a portion of the piling wall profile with a connecting endsection

Additional features, advantages and details of the invention will now bedescribed with reference to the single FIGURE.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Because the double T-shaped piling wall profile is mirror symmetric,only a portion of the piling wall profile produced according to theinvention is shown in cross-section.

The piling wall profile 1 includes flange sections 3 which are connectedin the center. Club-shaped connecting end sections 4 adjoin the flangesections 3 for receiving interlocks (not shown in the figure).

The outside contour of the flange section of a hot-rolled standardpiling wall profile is indicated by the dotted profile line 9 which isoriented essentially horizontally.

In the depicted exemplary embodiment, the inside of the flange sections3 is shown as being tapered toward the outside in form of a wedge.However, parallel flange sections 3, with the adjoining connecting endsection 4 adjoining the flange sections 3, can also be produced.

Starting with the outside dimension of the standard piling wall profileindicated by the profile line 9, the increase in the wall thickness 2limited to the flange section 3 during the hot rolling process isattained by grooving the finishing rollers. According to the invention,the wall thickness 2 can be increased on one or both outer surfacesand/or on one or both inner surfaces of the flange sections 3.

As shown in the figure, the club-shaped connecting end section 4 has theoriginal geometry of the standard profile, so that the standardinterlock can still be used.

Advantageously, the wall thickness 2 is increased only to a point wherethe maximum profile height of the standard profile, as defined by thevertical spacing between the club tips of the opposing flange halves, isnot exceeded. However, the increase in the wall thickness 2 may begreater, depending on customer requirements.

It is also evident from the diagram in the figure that the transition 5from the increased wall thickness 2 to the club-shaped connecting endsection 4 does not include a step.

In the depicted exemplary embodiment, the surface contour of theincreased wall thickness 2 extends essentially horizontally, andtransitions with a conically shaped section 6 and adjoining arcuatesection 7 into the connecting end section 4.

Optionally, the surface contour of the increased wall thickness 2 canalso have a sinusoidal, concave or convex shape, depending on thecustomer requirements.

1. A double T-shaped piling wall profile made of steel, comprising: twoflange sections, each having an adjoining club-shaped connecting endsection adapted to receive an interlock; a web connecting the flangesections; wherein, as viewed in cross-section, at least one of the twoflange sections has a convex bulge disposed between the club-shapedconnecting end sections, with the convex bulge increasing an averagewall thickness in the flange section while the connecting end sectionmaintains a constant dimension, with the increase in the average wallthickness being produced by hot rolling the piling wall profile.
 2. Thepiling wall profile of claim 1, wherein the increased wall thickness isproduced during finish rolling.
 3. The piling wall profile of claim 1,wherein the increased wall thickness is produced on at least one of anoutside or an inside of a flange section.
 4. The piling wall profile ofclaim 1, wherein the two flange sections are mutually parallel.
 5. Thepiling wall profile of claim 1, wherein the two flange sections are notparallel to one another.
 6. The piling wall profile of claim 1, whereinthe average wall thickness in the flange section is increasedindependent of a geometry of the adjoining club-shaped connecting endsection.
 7. The piling wall profile of claim 3, wherein the increasedwall thickness on the outside or inside of the flange gradually changesover via a step-less transition into the club-shaped connecting endsection.
 8. The piling wall profile of claim 7, wherein the step-lesstransition comprises a conically tapered section and an adjoiningarcuate section.
 9. The piling wall profile of claim 1, wherein theflange section having the increased wall thickness has a sinusoidalsurface contour.
 10. The piling wall profile of claim 1, wherein theflange section having the increased wall thickness has an essentiallyrectangular surface contour.
 11. The piling wall profile of claim 1,wherein the flange section having the increased wall thickness has aconcave or convex surface contour.
 12. A method for producing a doubleT-shaped piling wall profile made of steel and having two flangesections, each having an adjoining club-shaped connecting end sectionadapted to receive an interlock, and a web connecting the flangesections, with the convex bulge increasing an average wall thickness inthe flange section while the connecting end section maintains a constantdimension, the method comprising the steps of: providing a set of finishrollers having a surface contour shaped to produce, as viewed incross-section, a convex bulge with an increased average wall thicknessbetween the club-shaped connecting end sections in at least one of thetwo flange sections, providing a prefabricated rough profile havingdimensions close to final dimensions of the piling wall profile, and hotrolling the rough profile between the set of finish rollers to producethe piling wall profile with the convex bulge.